The diamond hollow drill with an external thread (Continental) R ½ inch is made of steel covered with protective lacquer and a diamond coating of sintered material.
Application note:
Drill must be sharpened before first use!
Drill speeds: ø 3-4 mm = 4000-5000 1/min - ø 5-15 mm = 2000-3000 1/min - ø 16-25 mm = 1500-2000 1/min - ø 26-50 mm = 500-1500 1/min - ø 51-100 mm = 300-800 1/min